The present disclosure relates to a recording head having an ink ejection nozzle for ejecting ink onto a recording medium such as a paper sheet, and to an ink-jet recording apparatus provided with the same.
An ink-jet recording apparatus that ejects ink to form images is capable of forming high-definition images and thus has been widely used as a recording apparatus such as a facsimile, a copy machine, or a printer.
In such an ink-jet recording apparatus, microscopic ink droplets (hereinafter, referred to as a mist) ejected together with ink droplets for image recording and a rebounded mist generated upon adhesion of the ink droplets to a recording medium adhere to an ink ejection surface of a recording head and is solidified. When the mist on the ink ejection surface is gradually increased to such an extent as to overlie an ink ejection nozzle, there might occur deterioration in linearity of ink ejection (flight deflection), failure of ink ejection, or the like, resulting in a decrease in printing performance of the recording head.
In many cases, the ink ejection surface has a water-repellent film formed thereon so that adherence of ink thereto is decreased. In a case of using water-based pigment ink, however, a repeated wiping operation by a wiper made of rubber causes pigment particles to act as an abrasive, thus causing the water-repellent film to be gradually ground away. As a result, it becomes likely that a mist adheres to the ink ejection surface, so that the ink ejection surface can no longer be kept clean.
As a solution to this, various methods for cleaning off a mist that has adhered to an ink ejection surface have been devised. For examples, there is known an ink-jet recording apparatus in which in order to clean an ink ejection surface of a recording head, a plurality of cleaning liquid supply ports are provided in a portion of the ink ejection surface on an outer side of a nozzle region in which a plurality of ink ejection nozzles are open (an upstream side in a wiping direction of a wiper). In this type of ink-jet recording apparatus, after a cleaning liquid is supplied through the cleaning liquid supply ports, the wiper is caused to move from an outer side beyond the cleaning liquid supply ports along the ink ejection surface, and thus the ink ejection surface can be wiped by using the wiper, while the wiper retains the cleaning liquid. In this manner, a recovery process for the recording head can be performed.